How to view systemd service logs?

The journalctl command is used to view systemd service logs.

To view logs for a specific service, for example nginx.service, you can run:

journalctl -u nginx.service

Keys and options:

• -u <unit> — filter by unit (service)
• -f — output in real-time mode (like tail -f)
• --since and --until — filter by time, e.g., --since "2024-06-01 10:00:00"

Example of viewing the last 50 lines:

journalctl -u nginx.service -n 50

To view system logs without filtering by service, simply use journalctl.

You can also combine with sudo if you need logs that are access-restricted:

sudo journalctl -u nginx.service